Xdrip/G6 restart fail

I recently discovered the joy of restarting G6 sensors via Xdrip and entering the true start date. Doing so, the initial readings have been very close to true and no longer run 100+ mg/dl off, requiring a massive calibration. However, the last two times I’ve attempted this, it has failed. I find a message in the event log that states “cannot rewind start time beyond [true sensor start date]”. Frustratingly, it doesn’t show any error until you go looking for it, the startup countdown timer just never starts and the home screen says “sensor is still warming up” at the top, and “stopped” at the bottom. Nothing ever happens at the end of the warmup.

I don’t think I’ve changed anything since successfully doing so. I’ve only ever used native mode. Running an 8J transmitter.

The internet and Facebook group haven’t turned up anything useful for this. Any suggestions?